Hello Alexey,
> When using postresql 7.4 or 8.0, odbc:sql_query returns error result if
> DELETE query remove no records from table, while it should return {update,0}:
This is a known problem that was pointed out more or less a month
and a half ago:
http://www.erlang.org/ml-archive/erlang-questions/200509/msg00422.html
After a few discussion, the conclusion was that it was indeed a bug
in the ODBC Erlang code (it was precisely identified and located), and
they have created a ticket for it to be fixed. So the only thing to do
is waiting and maybe fixing the code you are running meanwhile.
Best regards,
Laura M. Castro